* [PATCH net-next 0/3] bpf: Misc improvements and a new usage on bpf obj name
@ 2017-10-06 4:52 Martin KaFai Lau
2017-10-06 4:52 ` [PATCH net-next 1/3] bpf: Change bpf_obj_name_cpy() to better ensure map's name is init by 0 Martin KaFai Lau
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: Martin KaFai Lau @ 2017-10-06 4:52 UTC (permalink / raw)
To: netdev; +Cc: Alexei Starovoitov, Daniel Borkmann, kernel-team
The first two patches make improvements on the bpf obj name.
The last patch adds the prog name to kallsyms.
Martin KaFai Lau (3):
bpf: Change bpf_obj_name_cpy() to better ensure map's name is init by
0
bpf: Use char in prog and map name
bpf: Append prog->aux->name in bpf_get_prog_name()
include/linux/bpf.h | 4 ++--
include/uapi/linux/bpf.h | 8 ++++----
kernel/bpf/core.c | 17 +++++++++++++++--
kernel/bpf/syscall.c | 5 ++---
tools/include/uapi/linux/bpf.h | 8 ++++----
5 files changed, 27 insertions(+), 15 deletions(-)
--
2.9.5
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH net-next 1/3] bpf: Change bpf_obj_name_cpy() to better ensure map's name is init by 0
2017-10-06 4:52 [PATCH net-next 0/3] bpf: Misc improvements and a new usage on bpf obj name Martin KaFai Lau
@ 2017-10-06 4:52 ` Martin KaFai Lau
2017-10-06 4:52 ` [PATCH net-next 2/3] bpf: Use char in prog and map name Martin KaFai Lau
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Martin KaFai Lau @ 2017-10-06 4:52 UTC (permalink / raw)
To: netdev; +Cc: Alexei Starovoitov, Daniel Borkmann, kernel-team
During get_info_by_fd, the prog/map name is memcpy-ed. It depends
on the prog->aux->name and map->name to be zero initialized.
bpf_prog_aux is easy to guarantee that aux->name is zero init.
The name in bpf_map may be harder to be guaranteed in the future when
new map type is added.
Hence, this patch makes bpf_obj_name_cpy() to always zero init
the prog/map name.
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
---
kernel/bpf/syscall.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 0048cb24ba7b..d124e702e040 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -322,6 +322,8 @@ static int bpf_obj_name_cpy(char *dst, const char *src)
{
const char *end = src + BPF_OBJ_NAME_LEN;
+ memset(dst, 0, BPF_OBJ_NAME_LEN);
+
/* Copy all isalnum() and '_' char */
while (src < end && *src) {
if (!isalnum(*src) && *src != '_')
@@ -333,9 +335,6 @@ static int bpf_obj_name_cpy(char *dst, const char *src)
if (src == end)
return -EINVAL;
- /* '\0' terminates dst */
- *dst = 0;
-
return 0;
}
--
2.9.5
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH net-next 2/3] bpf: Use char in prog and map name
2017-10-06 4:52 [PATCH net-next 0/3] bpf: Misc improvements and a new usage on bpf obj name Martin KaFai Lau
2017-10-06 4:52 ` [PATCH net-next 1/3] bpf: Change bpf_obj_name_cpy() to better ensure map's name is init by 0 Martin KaFai Lau
@ 2017-10-06 4:52 ` Martin KaFai Lau
2017-10-06 4:52 ` [PATCH net-next 3/3] bpf: Append prog->aux->name in bpf_get_prog_name() Martin KaFai Lau
2017-10-07 22:29 ` [PATCH net-next 0/3] bpf: Misc improvements and a new usage on bpf obj name David Miller
3 siblings, 0 replies; 5+ messages in thread
From: Martin KaFai Lau @ 2017-10-06 4:52 UTC (permalink / raw)
To: netdev; +Cc: Alexei Starovoitov, Daniel Borkmann, kernel-team, Jakub Kicinski
Instead of u8, use char for prog and map name. It can avoid the
userspace tool getting compiler's signess warning. The
bpf_prog_aux, bpf_map, bpf_attr, bpf_prog_info and
bpf_map_info are changed.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@fb.com>
---
include/linux/bpf.h | 4 ++--
include/uapi/linux/bpf.h | 8 ++++----
tools/include/uapi/linux/bpf.h | 8 ++++----
3 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index a67daea731ab..bc7da2ddfcaf 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -56,7 +56,7 @@ struct bpf_map {
struct work_struct work;
atomic_t usercnt;
struct bpf_map *inner_map_meta;
- u8 name[BPF_OBJ_NAME_LEN];
+ char name[BPF_OBJ_NAME_LEN];
};
/* function argument constraints */
@@ -189,7 +189,7 @@ struct bpf_prog_aux {
struct bpf_prog *prog;
struct user_struct *user;
u64 load_time; /* ns since boottime */
- u8 name[BPF_OBJ_NAME_LEN];
+ char name[BPF_OBJ_NAME_LEN];
union {
struct work_struct work;
struct rcu_head rcu;
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 6082faf5fd2a..a37ad348c436 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -230,7 +230,7 @@ union bpf_attr {
__u32 numa_node; /* numa node (effective only if
* BPF_F_NUMA_NODE is set).
*/
- __u8 map_name[BPF_OBJ_NAME_LEN];
+ char map_name[BPF_OBJ_NAME_LEN];
};
struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
@@ -253,7 +253,7 @@ union bpf_attr {
__aligned_u64 log_buf; /* user supplied buffer */
__u32 kern_version; /* checked when prog_type=kprobe */
__u32 prog_flags;
- __u8 prog_name[BPF_OBJ_NAME_LEN];
+ char prog_name[BPF_OBJ_NAME_LEN];
};
struct { /* anonymous struct used by BPF_OBJ_* commands */
@@ -869,7 +869,7 @@ struct bpf_prog_info {
__u32 created_by_uid;
__u32 nr_map_ids;
__aligned_u64 map_ids;
- __u8 name[BPF_OBJ_NAME_LEN];
+ char name[BPF_OBJ_NAME_LEN];
} __attribute__((aligned(8)));
struct bpf_map_info {
@@ -879,7 +879,7 @@ struct bpf_map_info {
__u32 value_size;
__u32 max_entries;
__u32 map_flags;
- __u8 name[BPF_OBJ_NAME_LEN];
+ char name[BPF_OBJ_NAME_LEN];
} __attribute__((aligned(8)));
/* User bpf_sock_ops struct to access socket values and specify request ops
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index cb2b9f95160a..f75ac330831d 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -230,7 +230,7 @@ union bpf_attr {
__u32 numa_node; /* numa node (effective only if
* BPF_F_NUMA_NODE is set).
*/
- __u8 map_name[BPF_OBJ_NAME_LEN];
+ char map_name[BPF_OBJ_NAME_LEN];
};
struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
@@ -253,7 +253,7 @@ union bpf_attr {
__aligned_u64 log_buf; /* user supplied buffer */
__u32 kern_version; /* checked when prog_type=kprobe */
__u32 prog_flags;
- __u8 prog_name[BPF_OBJ_NAME_LEN];
+ char prog_name[BPF_OBJ_NAME_LEN];
};
struct { /* anonymous struct used by BPF_OBJ_* commands */
@@ -869,7 +869,7 @@ struct bpf_prog_info {
__u32 created_by_uid;
__u32 nr_map_ids;
__aligned_u64 map_ids;
- __u8 name[BPF_OBJ_NAME_LEN];
+ char name[BPF_OBJ_NAME_LEN];
} __attribute__((aligned(8)));
struct bpf_map_info {
@@ -879,7 +879,7 @@ struct bpf_map_info {
__u32 value_size;
__u32 max_entries;
__u32 map_flags;
- __u8 name[BPF_OBJ_NAME_LEN];
+ char name[BPF_OBJ_NAME_LEN];
} __attribute__((aligned(8)));
/* User bpf_sock_ops struct to access socket values and specify request ops
--
2.9.5
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH net-next 3/3] bpf: Append prog->aux->name in bpf_get_prog_name()
2017-10-06 4:52 [PATCH net-next 0/3] bpf: Misc improvements and a new usage on bpf obj name Martin KaFai Lau
2017-10-06 4:52 ` [PATCH net-next 1/3] bpf: Change bpf_obj_name_cpy() to better ensure map's name is init by 0 Martin KaFai Lau
2017-10-06 4:52 ` [PATCH net-next 2/3] bpf: Use char in prog and map name Martin KaFai Lau
@ 2017-10-06 4:52 ` Martin KaFai Lau
2017-10-07 22:29 ` [PATCH net-next 0/3] bpf: Misc improvements and a new usage on bpf obj name David Miller
3 siblings, 0 replies; 5+ messages in thread
From: Martin KaFai Lau @ 2017-10-06 4:52 UTC (permalink / raw)
To: netdev; +Cc: Alexei Starovoitov, Daniel Borkmann, kernel-team
This patch makes the bpf_prog's name available
in kallsyms.
The new format is bpf_prog_tag[_name].
Sample kallsyms from running selftests/bpf/test_progs:
[root@arch-fb-vm1 ~]# egrep ' bpf_prog_[0-9a-fA-F]{16}' /proc/kallsyms
ffffffffa0048000 t bpf_prog_dabf0207d1992486_test_obj_id
ffffffffa0038000 t bpf_prog_a04f5eef06a7f555__123456789ABCDE
ffffffffa0050000 t bpf_prog_a04f5eef06a7f555
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@fb.com>
---
kernel/bpf/core.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index c6be15ae83ee..248961af2421 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -309,12 +309,25 @@ bpf_get_prog_addr_region(const struct bpf_prog *prog,
static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
{
+ const char *end = sym + KSYM_NAME_LEN;
+
BUILD_BUG_ON(sizeof("bpf_prog_") +
- sizeof(prog->tag) * 2 + 1 > KSYM_NAME_LEN);
+ sizeof(prog->tag) * 2 +
+ /* name has been null terminated.
+ * We should need +1 for the '_' preceding
+ * the name. However, the null character
+ * is double counted between the name and the
+ * sizeof("bpf_prog_") above, so we omit
+ * the +1 here.
+ */
+ sizeof(prog->aux->name) > KSYM_NAME_LEN);
sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
sym = bin2hex(sym, prog->tag, sizeof(prog->tag));
- *sym = 0;
+ if (prog->aux->name[0])
+ snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
+ else
+ *sym = 0;
}
static __always_inline unsigned long
--
2.9.5
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH net-next 0/3] bpf: Misc improvements and a new usage on bpf obj name
2017-10-06 4:52 [PATCH net-next 0/3] bpf: Misc improvements and a new usage on bpf obj name Martin KaFai Lau
` (2 preceding siblings ...)
2017-10-06 4:52 ` [PATCH net-next 3/3] bpf: Append prog->aux->name in bpf_get_prog_name() Martin KaFai Lau
@ 2017-10-07 22:29 ` David Miller
3 siblings, 0 replies; 5+ messages in thread
From: David Miller @ 2017-10-07 22:29 UTC (permalink / raw)
To: kafai; +Cc: netdev, ast, daniel, kernel-team
From: Martin KaFai Lau <kafai@fb.com>
Date: Thu, 5 Oct 2017 21:52:10 -0700
> The first two patches make improvements on the bpf obj name.
>
> The last patch adds the prog name to kallsyms.
Series applied, thanks Martin.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2017-10-06 4:52 [PATCH net-next 0/3] bpf: Misc improvements and a new usage on bpf obj name Martin KaFai Lau
2017-10-06 4:52 ` [PATCH net-next 1/3] bpf: Change bpf_obj_name_cpy() to better ensure map's name is init by 0 Martin KaFai Lau
2017-10-06 4:52 ` [PATCH net-next 2/3] bpf: Use char in prog and map name Martin KaFai Lau
2017-10-06 4:52 ` [PATCH net-next 3/3] bpf: Append prog->aux->name in bpf_get_prog_name() Martin KaFai Lau
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